81837347 has 4 divisors (see below), whose sum is σ = 81859200. Its totient is φ = 81815496.

The previous prime is 81837317. The next prime is 81837367. The reversal of 81837347 is 74373818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74373818 = 2 ⋅37186909.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81837347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81837317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3728 + ... + 13325.

It is an arithmetic number, because the mean of its divisors is an integer number (20464800).

Almost surely, 2^81837347 is an apocalyptic number.

81837347 is a deficient number, since it is larger than the sum of its proper divisors (21853).

81837347 is a wasteful number, since it uses less digits than its factorization.

81837347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21852.

The product of its digits is 112896, while the sum is 41.

The square root of 81837347 is about 9046.3996705872. The cubic root of 81837347 is about 434.1607052075.

The spelling of 81837347 in words is "eighty-one million, eight hundred thirty-seven thousand, three hundred forty-seven".